Logo detection in pictures is of interest for several applications. As an example, such detection is used in a retargeting device in order to avoid including part of the logo in the retargeted picture. Others applications require the logo to be removed from the pictures. As an example, a program initially broadcasted on a TV channel (e.g., sports game) can be accessed later in catch-up mode on the same channel or can be sold to another TV channel for highlights. In the former case, the TV channel logo is usually removed to be replaced by a specific logo indicating that the program is in catch-up mode. In the latter case, the logo of the first TV channel is removed before the program is shown on the second TV channel.
It is known from European patent application published on Jan. 6, 2012 as EP2141658 to detect a logo in a picture using only saliency information. More precisely, a logo is roughly detected in search areas in the pictures based on saliency information. The search areas are for example the four corners of the picture. This solution can only handle the simplest case of static opaque logo with the constraint of the logo being present during the entire video segment to process. Furthermore, this solution fails when the logo is not the most visually salient area in the picture, for example when an object with high contrast is present in the picture.
On the other hand, it is known from a paper of Özay et al entitled “Automatic TV logo detection and classification in broadcast videos” published in EUSIPCO 2009 to detect a logo based on the accumulation of static edges over several pictures. More precisely, according to this method the edges are detected over N pictures. The edges are then accumulated over these N pictures. If N is high enough, the accumulated edges is a good information for detecting a logo. However, for a real-time application such as a video retargeting application, N cannot be high enough to get relevant information for logo detection.